Already looked at most of the recent threads on here about this.

Spent a chilly night last weekend on a hill in the Cheviots in my 25 yr old 2 season synthetic bag so fancy something warmer, lighter and smaller to spend my birthday money on.
Current bag is 1kg roughly and packs to 18×34 approx though would probably compress smaller.
I’m 190cm so it needs to be long
Down because it’ll be used mostly for single nights and I think hydrophobic down, waterproof outers and care will be ok.
Budget about £250
Looking at:
Mountain Equipment Helium 400
Rab Alpine Pro 400
Rab Ascent 300
Alpkit Pipedream 400

Possibly some Mammut ones?

Anything else?
Cheers